1. Field of the Invention
The present invention relates to a secondary battery system that includes a secondary battery, an abnormality detecting unit which detects one or more abnormalities of the secondary battery, and a signal generating circuit which outputs a signal to an externally connected device which operates in cooperation with the secondary battery based on detection information of the abnormality detecting unit, and also relates to a charging system for a secondary battery.
2. Description of the Related Art
Such a secondary battery system is provided in many cases in a configuration of what is called a battery pack, or in a configuration having a monitoring circuit of a secondary battery built in a casing of the secondary battery, for example. In the case of connecting between a charger and a secondary battery system by using the charger as the externally connected device, for example, the secondary battery system can be configured by combining a secondary battery with a circuit as a countermeasure against a case where the secondary battery has become in an abnormal state such as a case where an excessive current or voltage has been applied to the secondary battery during charging the secondary battery by the charger.
As such a configuration, there are considered a configuration in which a current interrupting device is arranged at a secondary battery system side in a supply path of a charging current from a charger to a secondary battery within a battery pack, a configuration in which a charge prohibition signal is output to a charger to cause the charger itself to stop a charge operation, and a configuration in which both of these configurations are included, as described in JP-A-2007-236033, for example.
As described in JP-A-2007-236033, according to the configuration in which a charge prohibition signal is output from a secondary battery side to a charger, a secondary battery system can have a configuration for stopping a charge current to a secondary battery with suppressing the increase of the manufacturing cost as much as possible, with use of a charge current interrupting function at a charger side.
However, it is not preferable to continuously use a secondary battery system that has once become in an abnormal state, even after the abnormal state has been improved.
For example, according to the configuration using the charge current interrupting function at the charger side, when this function is reset at the charger side, a charge operation to a secondary battery is restarted and the secondary battery that has become in an abnormal state, such as the secondary battery having received an excessive current or the like, is reused, which is not preferable.